    "the" (map #(unify % 
                       {:synsem {:cat :det
                                 :sem {:pred :definite
-                                      :of :none}
+                                      :of {:pred nil}}
                                 :def :def}})
               [{:synsem {:agr {:number :sing}}}
                {:synsem {:agr {:number :plur}}}])

   [{:synsem {:cat :det
              :def :partitivo
              :sem {:pred :some-of
                    :of :none}
              :agr {:number :plur}}}
    {:synsem {:cat :det
              :def :indef
              :sem {:pred :some-one-of
                    :of :none}
              :agr {:number :sing}}}]
   "speak"
   {:english {:past "spoke"

             :def :indef
             :mass false
             :sem {:pred :a-generic-instance-of
                   :of {:pred nil}}
             :agr {:number :sing}}}

   "abandon" {:synsem {:cat :verb
